1. Field of the Invention
The invention relates, generally, to the production of electronic circuits on the basis of electronic boards and, more particularly, to the production of three-dimensional electronic circuits with a view in particular to their integration into a touchscreen.
2. Description of the Relevant Art
Within the framework of the present description, three-dimensional electronic circuit is intended to mean a circuit that includes portions running in a plane different from the general plane of the circuit so as to locally orient the components carried by the circuit.
This may entail, in a mode of implementation, placing portions of the circuit opposite one another so as to place opposite one another components which operate jointly, for example light-emitting diodes and corresponding receivers.
An electronic board, or PCB, standing for “Printed Circuit Board”, is a support, in general a plate, making it possible to hold and to link electrically a set of electronic components, with the aim of producing a complex electronic circuit.
Electronic boards can be produced on several types of supports, among which are:                rigid supports, for example, “epoxy supports”, and        flexible supports, allowing the production of flexible printed circuits.        
In all cases, these supports are generally produced from a multilayer material and allow the soldering of components and connectors.
Document US 2013/258 575 describes in this regard an electronic apparatus comprising an electronic circuit produced by uniting two plane electronic boards by means of a flexible connector circuit. The flexible circuit is intended to be bent to give the electronic circuit a three-dimensional shape.
Reference may also be made to document U.S. Pat. No. 5,529,502 which describes an element for assembly and connection between a rigid electronic board and a flexible printed circuit. Such an element makes it possible to produce three-dimensional electronic circuits.
Thus, by end-to-end assembly of rigid electronic boards by means of flexible printed circuits, it is possible to produce a three-dimensional electronic circuit that includes rigid electronic boards exhibiting opposing faces.
It has however been found that the current processes for fabricating three-dimensional circuits impose a certain number of constraints.
Firstly, the electronic boards can only be fabricated flat.
Secondly, the positioning and the soldering of the electronic components and of assembly elements on a board can only be carried out flat.
Consequently, the fabrication of the electronic boards makes it necessary to place the electronic components and the assembly and connection elements flat on a circuit blank.
As will be detailed subsequently with reference to FIGS. 1A and 1B, a known technique thus consists in fabricating a PCB circuit board furnished with fold zones, such as is represented in FIG. 1A, and to join an end connector to obtain the three-dimensional circuit illustrated in FIG. 1B. As is appreciated, the use of such a connector and its joining to the PCB circuit complicates the production of the circuit.